The coloring of human hair has been practiced in various forms for thousands of years. In the last century these practices have evolved into three general types of haircolor: permanent, semi-permanent, and temporary. The term “permanent” refers to oxidative dying systems that permanently alter the hair's coloration. Reapplication occurs as the hair's new growth becomes noticeable. Oxidative hair dyes are usually sold in the form of a two-component kit. In one container is an aqueous alkaline composition that contains oxidative dyes and an appropriate vehicle. In the other container is a developer composition that has an oxidizing agent, usually hydrogen peroxide. The two compositions are mixed immediately prior to use and applied to the hair. The high pH of the mixture causes the hair shaft to swell, allowing the dye precursors to penetrate into the hair shaft. These dye precursors are oxidized, which combine to form larger molecules with color in the interior of the hair shaft. After an appropriate development time, the mixture is rinsed from the hair. The color of the hair is then permanently altered. This is the most popular form of haircolor for both men and women, as the results can be very natural looking and require maintenance only every 4–6 weeks.
Semi-permanent haircolor uses so-called preformed dye molecules that are not mixed with a developer prior to application. Therefore the size of the molecules does not change during the dye process. Semi-permanent dyes will wash out of the hair after six to twelve shampooings. Since no permanent change occurs to the hair's coloration, a natural looking blending of gray and pigmented hair can occur. The drawback with this type of a dye is that it exhibits a lack of durability and the development of off-tones that don't mimic the original color of the hair.
Temporary haircolor is applied to the hair surface, and is generally removed with one shampoo. Traditionally, these are used when a cosmetic effect is desired for one day.
Most products marketed use some type of insoluble pigment such as iron oxides, certified dye lakes, or titanium dioxide coated micas. They are contained in a styling gel media or some other appropriate vehicle that is often similar to mascara or other topical cosmetic. The drawbacks of these products are that they can only be useful for highlighting selected strands of hair to achieve a dramatic look. They are not practical when a natural allover color is desired as the compounds impart a “painted-on” appearance. Attempts have been made to improve the adherence of these pigments to the hair surface by using unique polymer compositions such as those disclosed in U.S. Pat. No. 6,042,619. More natural looking temporary hair colors were described in U.S. Pat. No. 5,454,841. These formulations incorporate a mixture of synthetic melanin with cationic surfactants in order to temporarily adhere the pigment to the hair. The expense and unavailability of the melanin makes these formulations impractical for commercial use. In addition the shade range is very limited for such a product, as melanin only permits the formulation of a black temporary hair color.
Manufacturers of haircoloring products have searched for temporary products that replicate the natural results achieved by a permanent haircolor, while having the feature of removability with one shampooing. The objective has been to provide what can be called a temporary hair color that can be used to preview a particular shade of color for determining the acceptability of the color or to provide an extreme hair color dye that can be used for theatrical purposes or for special occasions where extreme hair color of a temporary nature is desired.
The “try-on” concept for a particular haircolor that accurately mimics the permanent product would allow a consumer to preview haircolor without being concerned about the ease of complete removability with an ordinary shampoo. The “try-on” product would only be practical for the permanent haircolor subcategory of “demi-permanent” or “deposit only permanent”. These specialized colorants the permanent products are modified using reduced alkali levels that will essentially prevent the alteration of the hair's natural pigment. This lack of lightening of the natural pigment gives rise to a category that blends gray for a very natural appearance more like a semi-permanent color, but with all of the permanent advantages. These include durability and wearing on tone. Although this subcategory remains small for women's haircolor because it does not allow for the creation of blonde shades or the ability to make one's hair lighter, the majority of men's haircolorants rely on this technology. Realistic looking temporary haircolors have been devised by synthesizing fixative like polymers where the actual color moiety is included in the molecules such as those described in U.S. Pat. Nos. 5,735,907 and 5,876,463. The performance of these materials is acceptable for use in “try-on” products, however the complex nature of their manufacture and the expense involved has prevented commercialization of these formulation.
The applicant has found that a complex of a cationic dye and a water-soluble anionic polymer will provide a dye complex which may be dispersed in suitable vehicle to provide temporary hair color.